UK minister: 4 other banks in interest rate probe

LONDON 
Britain's Treasury chief says that four other banks are being investigated for allegedly participating in manipulating a key interest rate index.

Barclays Bank was fined $453 million Wednesday for its activities

U.K. Treasury chief George Osborne said Thursday that British banks HSBC and Royal Bank of Scotland are also subjects of investigation, along with Swiss bank UBS and U.S. bank Citigroup.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

A day after it was slapped with fines worth over $450 million, British bank Barclays PLC lost around 9 percent of its stock market value Thursday, while its peers saw their share prices dragged lower on concerns they would be dragged into the rate-fixing scandal too.

Lloyds Banking Group PLC and Royal Bank of Scotland PLC, were under pressure too after regulators on both sides of the Atlantic confirmed that other traders were involved in the manipulation of key interest rates that are used in everyday transactions such as buying a house.

"Banks were clearly acting in concert," said Andrew Tyrie, a British lawmaker, who is also chairman of the influential Treasury Committee in the House of Commons. "I fear it's not going to be the end of the story, that we are going to find that other banks have been involved."

Tyrie said his committee would summon Barclays chief executive Bob Diamond to explain what happened at the bank.

Though Diamond has decided to waive his 2012 bonus in the wake of the $453 million fines, he's facing calls to do more.

Prime Minister David Cameron, when asked whether Diamond should resign, said he thinks "the whole management team have got some serious questions to answer. Let them answer those questions first."

The fallout from the fines was clearly hitting Barclays' share price, which was trading 9 percent lower at 178 pence. That means the company is worth nearly 1.4 billion pounds ($3.4 billion) less than at the close of business on Wednesday.

Its peers Lloyds Banking Group and Royal Bank of Scotland were down around 6 percent amid concerns they would be dragged into the scandal too.

On Wednesday, U.S and British regulators imposed the fines on Barclays for providing false figures on borrowing rates between 2005 and 2009. Those false figures manipulated the London interbank offered rate (LIBOR) to Barclays' advantage.

The LIBOR is an average rate set by banks each morning that measures how much they're going to charge each other for loans. That rate, in turn, affects rates on many loans for consumers and businesses.

The U.S. Justice Department said Barclays would not face criminal prosecution, subject to certain conditions, but individual employees or officers could be prosecuted.

In response, Diamond waived any bonus for this year, as did finance director Chris Lucas, chief operating officer Jerry del Missier and Rich Ricci, the chief executive of corporate and investment banking.

Diamond said the decision reflected "our collective responsibility as leaders."

Martin Taylor, who was CEO of Barclays between 1995 and 1998, said the bank's board will have to make a decision whether Diamond can carry on in his post.